Build your own DSM2 transmitter module (its working!) - Page 36 - RC Groups
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Sep 13, 2012, 07:59 PM
I don't want to "Switch Now"
pmackenzie's Avatar
Lots of analog servos are not happy below 11 msec.
Even those of the same model number some will work, and others won't.
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Sep 13, 2012, 11:12 PM
Iron Savior's Avatar
Originally Posted by dave1993
every one of the dozen or so different servos (vigor, towerpro, hk, 500, 900, etc) work fine down to around 3ms. i actually use 8m rate because 8mhz avr is not capable of proper 20ms period. it will do 2ms but that wont work for obvious reasons.
You're referring to the ability of the servo to rapidly accept commands from a directly connected receiver (or whatever other device like an Ardupilot APM). I was talking about how rapidly you can send a command to the radio with good results--which can't handle more than one command every 10-ish milliseconds at best. This is a limitation of either the radio or the receiver and has little to do with the servo's capabilities beyond providing us with a way to visually observe the result of the commands sent to the radio.
Last edited by Iron Savior; Sep 13, 2012 at 11:20 PM.
Sep 13, 2012, 11:42 PM
Build to Fly? FLY to BUILD!
Legot's Avatar
I will confirm that karl's situation is not the radio at this point, but an incompatibility with the particular receiver. I have used the same code with the same radio and the same DSM2 module and have not had any problems.

I have not however used the setup with any of the UMX RXs, so some modification may be in order to make them compatible.
Sep 14, 2012, 12:03 AM
Yes, "that" Karl...
karl k's Avatar
I've changed this portion of the code to keep the frame rate from being too quick.
Any comments?

#define FRAMEinterval    15

void sendDSM2() {
  if(currentMillis - previousMillis > FRAMEinterval) // wait for proper frame rate
    previousMillis = currentMillis;                
    Serial.write(DSM2_Header, 2);
    Serial.write(DSM2_Channel, DSM2_CHANNELS*2);
Sep 14, 2012, 05:25 AM
RC beginner
Originally Posted by pmackenzie
Lots of analog servos are not happy below 11 msec.
Even those of the same model number some will work, and others won't.
that could be. we are talking at least couple hundred run at 8ms no problem but i may have just been lucky. all mine are super cheapie type. maybe "brand" servos are not so forgiviing.

savior, you are right about my comment referring to servo signals only. nothing to do with what goes in and out of the different rxs. thats more unpredictable. i know shorter than normal frame rates do cause trouble with escs hence the i2c and reflash cults.
Sep 14, 2012, 08:56 PM
Yes, "that" Karl...
karl k's Avatar
That didn't work.

Back to the drawing board
Sep 14, 2012, 11:31 PM
Yes, "that" Karl...
karl k's Avatar
Is the frame rate just slightly too long? This reading is taken on pin 3 (TX) of the atmega328

Name: ImageUploadedByTapatalk1347683100.058294.jpg
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Here is the PPM stream timing:

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Sep 15, 2012, 01:32 AM
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Legot's Avatar
Whats your clock speed?
Sep 15, 2012, 07:39 AM
Yes, "that" Karl...
karl k's Avatar
Sep 15, 2012, 02:24 PM
Yes, "that" Karl...
karl k's Avatar
Is 8MHz not proper?
Sep 15, 2012, 03:30 PM
Build to Fly? FLY to BUILD!
Legot's Avatar
It should work, I have no clue whats going on, do you have a different Rx you sould try? It could be something specific to the rx they use in the umx things.
Sep 15, 2012, 07:22 PM
Yes, "that" Karl...
karl k's Avatar
When I did have an AR6115 (?) laying around last time I built the module, it did the same thing.

I've tried different UMX planes and different transmitter boards (DX5e, HP6DSM, LP4DSM) and get the same result.

I just put the board from the HP6DSM that I used in the video into a 9x that uses ER9x firmware to send the signal to the board and it works properly. Nice and smooth. I'm stumped.

Everything should work properly built up on a breadboard, correct? The breadboard won't cause any problems with signal, will it?
Sep 23, 2012, 11:04 AM
Registered User

Futaba ch assignments

Has anyone tried the version of this thread using the Tiny 2313 using a futaba
transmitter? Are the channel assignments the same as the Spectrum?
I would like to use the Fatuba with indoor planes such as the Vapor It will only
function as long as the channels are the same.

Thanks Joe
Sep 23, 2012, 03:13 PM
Inciting Riots
village_idiot's Avatar
You mean the first version of this mod? Yes it works fine with a Futaba 9C and with my Microstar2000 when I set the channel order to Futaba.

I haven't installed the "digital direct" module into the Microstar yet, but it should work fine with the latest firmware in the encoder.
Sep 24, 2012, 02:02 PM
Registered User

Help with dx6i 2.4ghz board plug ripped out

This is probably way below the caliber of this thread by I need help with my DX6I
2.4 ghz board. I pulled the coaxial plug off the board while trying to change my antenna. Horizon will not sell me a knew plug in board and by the time I ship it too them and pay for parts it will be way too expensive. Can I just solder the center wire of the coaxial cable to the wire going from the now ripped out coaxial plug on the board. Is there also a hookup required on the sheath wire of the coaxial or does this stay neutral? If I just have to hook up the center wire to the wire going into the pc board I can handle the soldering job. If I also have to hook up the sheathing I don't think I would have much luck with that.

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